The present invention relates to the manufacturing of electric circuits and pertains particularly to improved flex panels of circuitry and methods of manufacture.
Flex circuits are widely used in the electrical and electronic industry today in a wide variety of applications. A flex circuit is typically what is referred to as a printed circuit on a flexible backing or insulation sheet. The circuit tracings are typically formed of a metal foil, such a copper and the backing is usually a polymer, such as polyamide. Many printed circuits are made in large numbers on large sheets of laminates of copper foil and insulating polymer. The circuits are made in large numbers on the sheet by a photoetching process. This is a well-known process and it is not believed that details need to be given at this stage.
The circuits, once formed and completed on the sheet of laminate, are then separated into the individual circuit units. A number of techniques for carrying out this separation process are presently used. One process is by laser cutting by large expensive laser machines. This is a very expense process and requires expensive equipment which many small manufacturers cannot afford.
Another process of separating the circuits is by what is sometimes called a steel rule die. This involves the construction of a steel die forming the precise outline of the cut to be made and of the precise dimensions to cut out the individual circuit units. The die is mounted in and operated by a large hydraulic or pneumatic press. This also requires very expensive machinery and requires very accurate cutting dies. Any change in the circuit requires a complete reconstruction of the die. This is also a very expensive process.
Many smaller companies separate the circuits by means of an exacto knife. Workers very carefully and meticulously trace out the circuit with an exacto knife. One major difficulty with this process is that frequently small nicks are left in the insulating backing which results in tears and frequently shorting of the circuit. Some companies also have workers cut out the circuits with scissors. These two processes are laboriously time-consuming.
There is a need for a single effective and inexpensive method and structure for separating flex circuits from panels of circuits.